Expansive drill bit for cable tools and the like



1927" J. P. MILLER EXPANSIVE DRILL BIT FOR CABLE TOOLS AND THE LIKEFiled Aug. 5. 1922 2. Sheets-$heet l INVENTOR J .1. P1111011,

44 TTOR/v/EYS July 1927' J. P. MILLER.

EXPANSIVE DRILL BIT FOR CABLE TOOLS AND THE LIKE Filed Aug. 5. 1922 2Sheets-Sheet 2 M Y. m a w s v m 4 Y\\\\ \M\\\\ \xi \\m% mmgag M w W flMEREEEEEE K Patented July 26, 1927.

UNITED STATES 1,637,268 PATENT OFFICE.

JESSE PERKINS MILLER, OF HOUMA, LOUISIANA, ASSIGNOR OF ONE-HALF TO J. H.THATCHER, 0F HOUMA, LOUISIANA.

EXPANSIVE DRILL BIT FOR CABLE TOOLS AND THE LIKE.

Application filed August 5, 1922. Serial No. 579,851.

My invention relates to improvements in well drills and it consists ofthe construction-s, combinations and mode of operation herein describedand claimed.

An object of the invention is to provide a bit for cable tools designedin such a manner that it will pass through a casing and have thecapability of opening beyond the end of the casing and drill a holelarge enough for said casing to freely follow.

Another object of the invention is to provide a bit which maybe operatedas an underreamer which will ream a hole already drilled under a casingto such size that the casing will freely pass.

A further object of the invention is to provide an underreamer whichwill ream the hole already made in the productive stratum and thus causethe well to produce more oil, gas, etc.

A further object of the invention is to provide an underreamer whichwill enlarge the bottom of the oil well so that it will hold moredetritus and therefore require cleaning at less frequent intervals.

A further object of the invention is to provide an underrealner of suchrigid construction that fishing operations are reduced to a minimum.

Other objects and advantages will appear in the following specification,reference being had to the accompanying drawings, in which:

Fig. 1 is a longitudinal sectional View illustrating the arrangement ofthe expansive drill bit, the blades being closed as in lowering the bit,

Fig. 2 is a view similar to Fig. 1, the blades being extended or openedas in the cutting operation,

Fig. 3 is a detail cross section on the line 3 3 of Fig. 2, showing theblade-retaining pins,

Fig. 4 is a section of the blade taken on the same plane as the .line 33 of Fig. 2,

Fig. 5 is a cross section on the line55 of Fig. 2,

Fig. 6 is a detail perspective view of one of the blades,

Fig. 7 is a longitudinal section of a slight modification of theexpansive drill bit, illustrating the use of a spring lifting device insubstitution of the hydraulic lifting device in Figs. 1 and 2,

Fig. 8 is a side elevation of a form of blade 3, 1921, Serial N 0.489,522 which has since become Patent No. 1,448,762, issued March 20,1923. The expansive drill 'bit of that application is more particularlyadapted for use in connection with rotary drilling tools, whereas theexpansive drill bit of this application is more particularly adapted forcable drilling and underreaming. blades 1 and 2 are opened by beingraised into the bit body 3. As one blade is identical with the other,the description of one will suffice for both.

Attention is directed to Fig. 6 which illustrates the blade 1 as anexample. The shank 4; is of semi-circular formation so that when the twoblades are fitted together (Fig. 4) the completed shank appears round incross section. The shank gradually enlarges downwardly from the head 5until it meets the shoulder 6, the eccentric shape of which arises as anatural consequence of the formation of the blade 1.

As shown in Fig. 5, the blade 1 (also the blade 2) is considerablythicker at'its outer periphery or cutting edge than at the inner edge.The curvatures 7 and 8, which respectively represent the outer and inneredges of the blade, are struck on the arcs of a circle the diameter ofwhich would embrace both blades when closed as in Fig. 1. This being so,the reader will doubtless inquire why the shoulders 6 should present theappearance of parts of an eccentric as in Figs. 4 and 6.

Reference to Figs. 1 and 2 will disclose the axial lines 9 and 10 of theshanks 4 of the blades to extend in directions different from the axiallines 11 and 12 of the blades 1 and 2, there being a definite reason forthis formation.

When the blades 1 and 2 are down and closed as in Fig. 1, the axiallines 11 and 12 of the blades coincidewith eachother and with the axisof the bit body 3. The axial lines 9 and 10 of the shanks 4, however,form The Ill

angles with each other and: with the axial line of the bit body 3. Asthe bit shanks 4 are raised into the bit body their axial lines 9 and 10are forced to coincide with each other and with theaxial line of thebitbody,

of the shank, and also explains the manner 5 in which the bIadesareopened when moved inwardlyinrespect to the bit body.

Each head 5 has a recess 14; the two of which when fitted togetherdefine a pocket or chamber intended to be occupied by the boss 15 of thepiston rod 16. Connection of the piston rod is made with the head by apin'17 which passes through transversely of the chamber 14* and occupiesholes 18 in the sides of the two heads 5.

At a place a short distance below the chamber 14 each shank is cut outat the sides at 19 to define spaces for the retaining pins 20 whichlimit the vertical movement of the bit'by virtue of the engagement ofthe shoulders 21 provided by the formation of'the' spaces 192 When thebit is closed as in Figure 1, the shoulders 21 engage the retaining pinsand thus limit the outward movement of the hit. When the bit is openedas in F ig. 2, the conical base portion 13 of the shank fits tight inthe conical entrance 1 1 to the opening 15 of the bit body. Shoulders 6rest against the lower end of the bit hody andthe inward movement of thebit is thus limited.

The hydraulic liftin device in Figs. 1 and 2 comprises a cylinder 23into which the piston'rod 16 extends. The lower ald r the liftingcylinder isclosed by a cap 24 throiigh "whit-lithe rod 16 passesandwhich carries a packin 25 for the obvious purpose of malt ing a tightjoint between the movable piston rod and the lifting cylinder.

The upper end of the piston rod carries a piston 26, and situatedbetween the piston and the lower end of the cylinder is a liftingspring2T, the function of which is to reta'rd the up'and downmovelnentsof the bitwhen the bit body 3 is moved up and dhwn initiallyfor the purpose of spreading the blades into the cutting position.Mounted above the piston 26 and forming a part thereof is-a' casing 28which serves the function-of a valve cage in that it carriesthe inwardlyopening fluid valve 29 and outwardly opening orexhaust valve 30. p

A spring 31' keeps the inlet valve 29 closed, and a more powerfulspriiig32 keeps the outlet valveclosed. The lifting cylinder 23 is relativelystationary because it is respect to the bit body 3* and are hanging downin the closed position. It is necessary to soread the bladesl and'2 intothe position in ig. 2 before the d'rilling can commence. Itis here thatthe function of the lifting device in the bore 15 ofthe bit body enteis.Bear in mind that the lifting device is supported in the bore 15 by thesupporting pin 33 and while most of the weight of the bit blades 1 and 2is supported by the retaining pins 20 (by virtue of the enga einent ofthe shouldeis 21) yet a part of tie weight of the bit is supported bythe spring 27 due to the engagement thereof with the piston 26. Whilebeing handled at ordinary speeds (as going into the hole) the blades 1and 2 stay down as in Fig. 1, dividing their weight be tween theretaining" pins 20 and the spring 27, as just stated.

U on reaching the scene'of the cutting op eration, the bit body 3'should be worked up and down by a few rapid strolces'so that the fluid Fabove the piston 26 is worked down through the inlet valve 29 beneaththe piston 26, causing the progressive raising of the piston in respectto thelift'ing cylinder 23 and consequently the raising of the bitblades until the conical shank 13'engages' the conical opening 14 in theend of the bit body and the blades assume the spread position in Fig. 2.The blades are raised and spread step by step by a non-retrogradeaction, being positively prevented from moving bacltwards when each stepis accomplished. Of necessity, the piston 26 must have openings throughwhich the fluid may pass from above to the space below.

Now consider the manner in which the fluid is transferred as stated. Asthe walking beam of the drilling apparatus on the surface drops the stemand bit, the natural expansive force of the compressed spring 27 tendsto slack'en the downward speed of the blades by virtue of its pressingup underneath the piston 26. In other words, the spring 27 tends toslacken the downward movement of the bit. The resultant upward relativemovement of the piston 26 in the lifting cylinder 23 causes the valve 29to open and permit some of the fluid above the piston to how into thespace heneath the piston 26. When the relative movement of the bit bodyceases, the valve 29 again closes.

Inn

When the aforesaid walkinv beam nears the top of its upward stroke, thebit body 3 and blades 1 and 2 will be found to rise to gether but theblades being supported by the expansive spring 27 will not slow down asreadily or rapidly as the bit body does, and again the result is arising of the piston 26 in the lifting cylinder 23. Again, fluid willpass down through the valve 29 and it will be found that only a fewstrokes are required to force enough fluid beneath the piston 26 tocause the proper elevation of the blades in respect to the bit body.Should it so happen that the reamed hole at the bottom of the Well isdeep enough, the foregoing results may be obtained e. the blades may beopened) by dropping the tool a short distance and merely catching thecable several times by applying the brake. This produces a succession ofjerks which have the effect of intermittently opening the valve 29 sothat the fluid is led beneath the piston 26.

lVhen the bit is used to'drill, or when a hole to be reamed is smallerthan the bit when closed, the bit blades may be opened by merely restingthem on top of the small hole, whereupon the bit body 3 will move downaround the bit and. cause the shanks of the blades to ride up into thebore.

\Vhen pulling the bit out of the hole, the.

holders 6 of the blades will catch under the casing and pull the pistonrod 16 and piston 26 down against the tension of the spring 27. Theresulting pressure against the outlet valve 30 will cause that valveto-open against the tension of the spring 32 so that the fluid againpasses up into the space above the piston. The reader might inquire whythe outlet valve 30 does not open when pressure is imposed on the fluidafter it passes througl'i the inlet valve 29. As stated before, theclosing spring 32 is considerably stronger than the spring 31. of theinlet valve, and sufficiently strong to hold the outlet valve closedunder normal operating circumstances.

The spring lifting device in Fig. 7 constitutes a different constructionbut is intended to accomplish the same purpose as that of the hydraulicliftingdevice, namely, to extend the bit to an operative position. Thecylinder 22 corresponds to the lifting cylinder 23 in Fig. 1. A pltug-34closes the upper end of the cylinder, provides a means for mounting thelifting cylinder on a pin similar to the pin 33 in Fig. 1 and serves assupporting means for a pair ofsprings 36 and 37, the latter of which. isstronger than the former. Being of the same dimensions the liftingcylinder 23 may be used interchangeably with the hydraulic liftingcylinder 23 in the bore 15 of the bit body 3.

The spring 36 is suitably attached to and therefore supports a liftinglink 38 which '1 (Figs. land 2).

has a recess 39 adapted to receive the head 40 of a latch 41 which issupported by the other and stronger spring 37. The lifting link hasshoulders 42 adapted to engage the lower edge of the cylinder 23 whenthe bit is drawn up and assumes the open position. On a somewhat similarprinciple, the head lO has shoulders 43 and 44, the former to normallyengage the edge of the cylinder, the latter to engage the heel 41-5 atthe upper end of the recess 39. The bottom of the recess is beveled at46 to be engaged by a corresponding bevel 47 on the head of the latch.The bevel 46 is intended to force the latch 40 into the recess 39.

The operation of the spring lifting device is as follows: The liftinglink 38 terminates in a head 48 and this head is provided with a hole toreceive a. bit pin 17 a corresponding to the pin 17 in Fig. 1, for theobvious purpose of supporting the heads 5* of a pair of blades which maybe of the form disclosed in Fig. 1 or of either of the forms disclosedin Figs. 8 and 9. The spring 36 (like spring 27 in Fig. 1) supports partof the weight of the bit, the'other part being supported by theretaining pins.

Normally the blades are held down by their own weight and remainclosed.They even remain closed at ordinary lowering H speeds and will passthrough any casing through which the bit body itself i. passing. Onequick up and down motion of the tool will result in such a reaction ofthe spring 36 that the lifting link 38 will move up far enough to bringits recess 39 adjacent to the head 4-0 of the latch. Engagement of thebevels 46 and 47am cause the shoulder ll of the latch to ride beneaththe heel of the lifting link and bring the two into engagement with asnap. The stronger spring 37 now augments the spring 36 and the two pullthe bit upwardly in respect to the cylinder 23 until the bit blades areseated in bit body.

It seems an obvious expedient to use either expansion or compressionsprings in either of the foregoing types of lifting devices. Theunderlying reason for the opening of the bit in either n'iodilication isvery readily understood when one stops to consider that all freelyfalling objects move at the same rate. If one is retarded with respectto an other, naturally the retarded object falls slower. In the twoforms of the invention the springs retard the fall of the bit blades andin fact accelerate the fall of the tools and bit body in respect to theblades.

hen the tools with the bit body are dropped by the walking beam on thesurface, the blades falling slower-than the bit body rise up into thecone-shaped opening Also, when the tools are lifted, their momentumcarries them a distance'against gravity. All objects thrown aii equalyeloeity will rise to the sanie lieight against gravit but according tothe invention, the springs :issist the blades to r se faster thantheother parts of the bit, thus in eileCt retarding the tools and bitbody.

Since the blades rise higher than the bit body, it follows that but afew strokes of the beam at the top are required to raise and open thebit.

The modifications in Figs. 8 and 9 are in' tended to disclosevarioustypes 6f bit-blades which may be used" in connection Witlr the operativeposition by a series of up and down lifting devices. In Fig. 8, thelower end of the blzide 1*" is" cut away at an angle as at 49 so as tomake an underrearner bla de out of an ordiiiary bit blade which formerlyinclndeda' portion indicatedby the dotted lines. In Fig; 9, the blade Iis cut away at :30 and thickened at {if to make anun'deire'amer blade ofa very sturdy construction. The'cut away portion 50' makes a hollowunderreamer of the'bla de 1. 1

While the construction and arrangement of theimprov ed esipa'nsii edrill bit as herein described and claimed: istliat of a generally,preferred form, obviously modifications and changes may be made withoutdeparting from the spirit and scope of the invention as claimed; 7

1. In drilling apparatus, a drill haying es: pansive elements, and meansfor expanding said elements step by step to a permanent motions impartedto the drill.

2. In drilling apparatus, a drill havihg expansive elements, meansoperable to produce a non-retrograde e'xpandin'g action of said elementsto a permanent operative position by a series of up and down movementsimparted to the drill after the drill has passed the end or acasing'throii gh" which it is adapted to belowe'red but before thebottom of the bore is reached, and means to hold said elements in saidoperative position.

3'. In combination with means by which a tool is lowered into a well, atool carriedb'y said means comprising a bit bod'ynexpansive bladescarried by said body, and means operated by s'uccessivel lowering the(able anddroppin'gthe tool 1n the well then denly holding the cable andstopping the tool thereby to move the blades into and siistain them inan expanded and operative position on the bit body.

4;. A bit body having expansive blades', a lifting cylinder containingfluid and ocupying a bore in the bit body, means by which the cylinderis'supporte'd in the bore, retaining pins by which part of the Weight ofthe blades is supported While in'theclos'd' position, means extendingfrom the blades into said cylinder, resilient means hax ihg suchengagement both with a part of said extendin means and with the cylinde-to nieanswliicli" act upon the flui furnish thecreiimindr or assupportfor the, blades while in said closed osition, and

d during a series" of u I and down movements of the bit body to holdtheblades in the expandedandj operative position to which they are moved bysaitl movements. L

5. A? well drill comprising a hit body, ex pah'sive bliides carriedthereby, means which exercises a supporting function for the blades,resilient means in connection with a part of said supporting means toassist said function, and means in connection with said supporting meanscausing the transfer of fluid thereunder byvirtue of a s'eries of up anddown movements of the drill to cahse the supporting meansto moveinwardly in respect tothe drill body and shift' the blades tda'nexpanded position. v

6. A well drill comprising a bit; body, a chamber by )Vhich a" fluid iscontained, eitp'arisive'blades carried by means which extends intosaidchamber, resilient means in connection with said carrying nieans toexerrise a supporting function therefor, and means in connection withsaid'carrying means adapted: to transfer fluid from the space above m aspace below a part of said carryin' ineans to'canse the lifting thereofand the moving of the blades to an expanded position.

7. A" Well drill comprising a bit body having eipansive blades, a rod inconnection with the blades having a spring which partly supports theWeight ofthe blades, a fluid chamber, and a piston on the rod hfavingvalve mechanism to transfer the fluid under thepiston under compressionby virtne of the initial up and down movement of the drilito lift theblades in respect to the bit body and hold them in the expanded indoperative pfosition.

8'. A well d'rillcompri'sing abi't body having' a; bore, a fluidcylinder suspended in said bore, expansive blades carried by a rodhaving a piston" o'ocupyiiig said cylinder, a spring disposed under thepiston to exercise a supporting function for the blades, and a valvemechanism embodied in the piston adapted es transfer fluid from thecylinder under the piston by the action of a series of upaiid dotvn moements of the drill to raise the piston and blades in respect to tliebit body and lock them in the expanded'position d'uringoperation.

9'. A Well drill comprising a bit body havinga bore, a fluid cylindersuspended in said bore, expansive blades carried by a rod having apiston occupying said cylindeif, a spring disposed under" the piston toexercise a supporting function for the blades, a valve mechanismembodied in the piston adapted to transfer fluid from the cylinder underthe piston by the abtion of a series of up and down movements er the armto raise the iii piston and blades in respect to the bit body and lockthem in the expanded position during operation, and a valve embodied inaid valve mechanism enabling the re-transference of the fluid above thepiston when the blades, rod and piston are bodily pulled out by catchingthe former on the well casing in withdrawing the drill.

10. An underreamer comprising a bit body, expansive blades normallyclosed and extended in respect to the body, a compressed spring havingconnection with supporting means of the blades to retard the actioi. ofgravity on the blades when the bit body is lowered, and valve mechanismadapted to transfer fluid to a place beneath said supporting means ateach retarding action of the spring during a series of up and downmovements of the bit body, to cause the elevation of the blades inrespect to the bit body and the expansion thereof to an operativeposition.

11. A well drill comprising a bit body having a bore with a conicaloutlet, expansive blades having conical shanks situated in said outlet,and instrumentalities in said bore including means for raising theblades in respect to the bit body upon performance of a series of up anddown motions thereof, and other means to sustain the blades at eachraising movement and finally cause said conical shanks to aline with theconical outlet and thereby expand the blades to an operative position.

12. A drill comprising a bit body adapted to be supported, expansivebits carried by and hanging loose from the body when closed, and meansreacting upon being subjected to a succession of impulses impartedthereto by said support to draw the bits up and means to sustain thebits after each reaction finally holding them in engagement with thebody.

13. A drill comprising a bit body adapted to be supported, expansivebits carried by and hanging loose from the body when closed, afluid-filled cylinder in the body, a rod connected to the bits extendinginto the cylinder where it has a piston with a valve, and a spring whichpresses up under the piston and is adapted to supplement the inertia ofthe piston, rod, and bits upon either an up or down impulse of the bitbody by a sudden stopping of the support to thereby cause the valve toopen and pass fluid under the piston to raise the bits until theycontact the body.

14. A drill comprising a bit body adapted to be supported, expansivebits carried by and hanging loose from the body when closed, afluid-filled cylinder in the body, a rod connected to the bits extendinginto the cylinder where it has a piston with a valve, a spring whichpresses up under the piston and is adapted to supplement the inertia ofthe piston, rod, and bits upon either an up or down impulse of the bitbody by a sudden stopping of the support to thereby cause the valve toopen and pass fluid under the piston to raise the bits until theycontact the body, and another valve in the piston opening oppositely tothe first valve being adapted to let the fluid pass back up when thebits are hooked under a casing in withdrawing the drill.

15. Apparatus of the character described comprising a freely up and downmovable body, a cutting member, yieldable means supplying a partialsupport for the cutting member on the body and producing an accelerationof the cutting member diflerent from that of said body, and liquid meanschecking movement of said cutting member in one direction at the end ofeach accelerated movement.

16. In drilling apparatus, a drill having expansive elements, and fluidmeans embodied in the drill for expanding said elements, step by step toa permanent operative position by a series of up and down motionsimparted to the drill.

17. A drill comprising a bit body adapted to be supported, expansivebits carried by and hanging loose from the body when closed, and meansreacting upon being subjected to a succession of impulses impartedthereto by said support to draw the bits up step by step, and means tosustain the bits after each reaction, said bits and adjacent parts ofthe body being so shaped as to expand the bits as they are raised.

18. In drilling apparatus, a body having cutting elements, means whichis movable relatively to said body and from which said elements aresuspended, said means having a piston, means containing a fluid intowhich said relatively movable means and piston extend, and valve meansincorporated in the piston permitting such transfer of fluid through thepiston as will move the cutting elements in one direction step by stepand hold them in position at the end of each step.

19. Apparatus of the character described comprising expansive elements,and means requiring an up and down motion of the apparatus to expandsaid elements to an operative position.

JESSE PERKINS MILLER.

